Many of today's computers, computer peripherals and other electronic products are designed to receive removable devices or cards, conforming to standards established by the Personal Computer Memory Card International Association (PCMCIA). These standards define the electrical and physical specifications of the card, including the interfaces between the card and the port or slot into which the card is inserted, as well as three card form factors, called Type I, Type II and Type III.
PCMCIA cards may be used for various purposes such as, for example, to establish a communications link between portable computer users and corporate networks, the Internet and other on-line services from a wide variety of locations; to supplement the semiconductor memory of a personal or notebook computer; to store information or data for use by the host system; or to reconfigure the host system in response to information stored in the card.
PCMCIA cards typically include a substrate, usually rectangular and in the form of a printed circuit board (PCB) which contains electronic components including integrated circuit packages. The PCB is attached along one of its edges to a multiple connector typically including a connector of molded plastic having multiple contacts for electrically connecting the card to the host system by way of a port or slot. A typical PCMCIA card further includes a molded plastic, insulative frame and a sheet metal cover including upper and lower cover panels enclosing the PCB and having forward margins secured to upper and lower surfaces of the plastic connector. The metal cover not only protects the PCB, but also acts as a shield against electromagnetic interference.
Although effective as a protective shield against both physical damage and EMI, the metal shield tends to be limited in shape and is aesthetically less appealing than plastic. More specifically, because the panels tend to be pressed from sheet metal, multiple press runs are required to obtain the more intricate shapes that are desirable for today's highly-stylized PCMCIA cards which conform closely to the components they contain. As the number of press runs increases, however, so does manufacturing costs. Therefore, the shape of a metal panel usually is a compromise between the desired shape and manufacturing costs. Additionally, metal panels tend to be less aesthetically pleasing than plastic due to limitations in the texture and finish of the panel body.
Shape and aesthetic considerations thus tend to favor the use of plastic for such panels, given the moldability and flexibility plastic affords. Plastic panels have several shortcomings, however, which have traditionally discouraged their use. Specifically, plastic panels tend to be difficult to join to complementing metal panels using traditional techniques such as adhesion. A traditional approach for avoiding a plastic-to-metal connection is to use plastic inserts within the complementing metal panel and then ultrasonically weld the plastic inserts to the plastic panel. Although effective, this approach requires additional components and relatively complex metal panels and manufacturing steps, and therefore tends to be relatively expensive.
Therefore, there is a need for a PCMCIA card configuration that facilitates the use of highly-moldable and aesthetically-pleasing materials such as plastics, while not sacrificing the strength and EMI protection offered by metal. Such a card should also be fabricated using convention techniques such as ultrasonic welding. The present invention fulfills these needs among others.